If the
HAZMAT situation at an Ogden, UT IRS building does turn out
to be some kind of attack, then this
article will have proven to be eerily prophetic:

Feb. 19--OGDEN -- Some Internal Revenue Service employees in
Ogden are expressing concern for their safety after a man
apparently intentionally flew his single-engine plane into an IRS
building in Austin, Texas, causing heavy damage and injuring at
least two people. "You are not safe," said a woman who works in
an IRS building at 23rd Street and Wall Avenue but declined to
give her name.

"Anybody can get you."

Another IRS employee who works in the same Ogden building
described the actions of the pilot in the Texas incident,
identified as Joe Stack, 53, of Austin, as "pretty sick" but
unpreventable.

"It could happen anywhere," the man said. "A lot of people don't
like the federal government."